Chapter 3. Selection of survey subjects

In this simplified field assessment, nutritional status is
usually measured only in children between the ages of 6 and 59 months.
Frequently, children in this age group will be the first to show signs of
undernutrition. They are generally highly vulnerable and in times of nutritional
crisis may show increased morbidity and mortality. Children under 6 months of
age (or about 60 to 65 cm long if age is not known), apart from being more
difficult to measure, are often still breast-fed and therefore satisfactorily
nourished. The upper limit of 59 months corresponds to approximately 100 to 110
cm in height of the reference population.

Because children in many developing countries are significantly
stunted, a sample with the 110 cm cut-off will often include many children over
5 years of age and a correspondingly smaller proportion of the younger and most
vulnerable children below 2 years. To maintain an adequate proportion of the
younger children, it is recommended to use 100 cm as the cut-off point. At this
stage, no distinction is made between sexes.

Target group for the survey: age 6 to 59 months or height
60 to 100 cm

In food emergencies, older children, pregnant and lactating
women, the elderly, and the disabled may also be considered high-risk groups.
They are generally not weighed and measured because there are no valid
references for most of these groups. Since the status of young children reflects
that of the general population, relief measures should also be extended to the
other vulnerable groups if not to the general population.

It should be noted that, if many older children and adults are
affected, the Body Mass Index (BMI = kg/m2) can be used for an
estimate in adults. The WHO expert committee on Physical Status: the Use
and Interpretation of Anthropometry described the condition of low BMI as
thinness, with the following three grades: